Unsaturated polyesters

ABSTRACT

An unsaturated polyester prepared by reacting under esterification conditions the following reactants; A. AN ETHYLENICALLY UNSATURATED DICARBOXYLIC ACID; B. TETRAHYDROPHTHALIC ANHYDRIDE OR ENDOMETHYLENE TETRAHYDROPHTHALIC ANHYDRIDE; C. AN ALIPHATIC SATURATED DICARBOXYLIC ACID OR A DIMER OR TRIMER OF AN ETHYLENICALLY UNSATURATED ALIPHATIC MONOCARBOXYLIC ACID; AND D. CYCLOHEXANEDIMETHANOL OR A MIXTURE OF NEOPENTYL GLYCOL AND A SECOND DIHYDRIC ALCOHOL. Upon crosslinking or curing the unsaturated polyester with a vinyl monomeric crosslinking agent, there can be obtained products having improved thermal stability properties.

United States Patent Fekete et a1.

[54] UNSATURATED POLYESTERS [72] Inventors: Frank Fekete, 4403 McKenzieDrive, Monroeville, Pa. 15146; John S. McNally, 457 Glenview Drive,Lower Burrell, Pa. 15068 [22] Filed: Oct. 20,1970

[21] Appl.No.: 82,544

[52] US. Cl. ..260/22 D, 260/22 CB, 260/75 UA, 260/75 A, 260/861,260/869, 260/871 [51] Int. Cl. ..C08f 21/02, C08g 17/12 [58] Field ofSearch ..260/86l, 75 U, 22 D [56] References Cited UNITED STATES PATENTS3,530,202 9/1970 Fekete et a1. ..260/861 3,533,999 10/1970 Fekete et a1......260/75 3,560,445 2/ 1971 Fekete et a1. ..260/75 FOREIGN PATENTS ORAPPLICATIONS 1,047,483 11/1966 GreatBritain 51 July 4, 1972 OTHERPUBLICATIONS Arkdzhovskii et a1., Sb. Tr., Vses. Nauch-Issled. Inst.Novykh Stroit. Mater. 7, 110- 20(1966) Primary Examiner-Melvin GoldsteinAttorney0lin E. Williams, Oscar B. Brumback and Synnestvedt & Lechner [57] ABSTRACT 17 Claims, No Drawings UNSATURATED POLYESTERS BACKGROUND OFTHE INVENTION This invention relates to unsaturated polyesters, to apolymerizable composition containing said polyester and a vinylmonomeric crosslinking agent and to the thermoset polymer prepared fromthe polymerized composition. More particularly, this invention relatesto an unsaturated polyester which upon being reacted with a vinylmonomeric crosslinking agent can be formed into a thermoset polymericarticle having improved properties, including improved thermal stabilityproperties.

Unsaturated polyesters which are prepared by reacting an ethylenicallyunsaturated dicarboxylic acid (or an anhydride thereof), a dihydricalcohol and, optionally, a saturated dicarboxylic acid (or an anhydridethereof) are well known. An example of such a polymer is one preparedfrom maleic anhydride, ethylene glycol and phthalic anhydride.

Such polyesters can be reacted or cured with a vinyl monomericcrosslinking agent, such as styrene, and formed into articles which havegenerally good physical and electrical properties and good chemicalresistance and weathering characteristics. Fibrous reinforcements, suchas glass fibers, are added usually to the polymerizable composition forthe purpose of improving the strength of articles made therefrom.

A shortcoming of various of the heretofore known cured polyester resinsof the type described above has been their tendency to degrade whenexposed to elevated temperatures for even relatively short periods oftime-for example, a few hours at temperatures in excess of 200 C. Undersuch conditions, the properties, for example the physical and electricalproperties, of the cured polyester resin tend to suffer as a result of asoftening of the resin.

In addition, such properties tend to deteriorate as a result of adegradation of the cured polyester resin due to volatization ofingredients comprising the resin. Analysis of a cured resin that hasbeen exposed to elevated temperatures for even relatively short periodsof time shows that the resin has lost weight and its properties do notmeasure up to those it had before it was heated.

There have been some developments designed to provide curedpolyester-type thermoset polymers having improved heat resistance orthermal stability. Speaking generally, the developments have includedthe formulation of the unsaturated polyester condensate from a specificcombination of reactants. However, it has been suggested that the heatdeterioration problem of the cured polyester resin is due not to thepolyester linkage of the resin but to the vinyl crosslinked portion ofthe resin.

Whatever the source of the problem, various of the heretofore proposedsolutions have disadvantages. For example, often the thermal stabilityproperties of the cured polyester resin are improved at the expense ofreducing other properties. Also, some unsaturated polyesters that can becured into thermoset articles having improved thermal stability tend tobe incompatible with vinyl monomeric crosslinking agents. This createsproblems in fabricating the polymerizable composition into the curedarticle.

Thus, it would be advantageous to have available cured polyester resinswhich have improved thermal stability properties and generally goodphysical and electrical properties, as well as the other excellentproperties that are present usually in this class of resins. This wouldenable the resins to be used in applications, particularly electricalapplications, where they 7 cannot now be used.

U.S. Pat. Nos. 3,530,202, 3,533,999 and 3,560,445 disclose unsaturatedpolyesters which upon being crosslinked with a vinyl monomericcrosslinking agent provide products which have high thermal resistance,good heat distortion values and good electrical properties, as well asgood mechanical and chemical properties. In addition, the polyesters ofthese patents are compatible with vinyl monomeric crosslinking agents.

The aforementioned U.S. Pat. No. 3,533,999 discloses an unsaturatedpolyester formed by the esterification of:

A. an acid reactant consisting essentially of:

1. 5 to 44 mole percent of tetrahydrophthalic anhydride orendo-cis-bicyclo (2.2.1 )-5-heptene-2,3-dicarboxylic acid anhydride andlower alkyl substituted products thereof; and

2. 6 to 45 mole percent of maleic anhydride; and

B. a dihydric alcohol reactant consisting essentially of:

l. 10 to 30 mole percent of 2,2-dimethyl-l,3-propanediol (neopentylglycol); and

2. 20 to 40 mole percent of a second dihydric alcohol.

The aforementioned ingredients are reacted under conventionalesterification reaction conditions. Thus, the mole ratio of the acidreactant, (A) above, and the dihydric alcohol reactant, (B) above,should be about 1 to 1; however, an excess of the dihydric alcoholreactant, for example about 10 percent by weight, should be used toallow for the loss of some alcohol as a result of its boiling off withthe by-product water that is formed. The esterification is carried outunder an inert blanket of gas, such as nitrogen, at a temperature withinthe range of l-220 C. for a period of about 6-20 hours until an acidnumber below preferably below 50 is obtained (based on milliequivalentsof KOH necessary to neutralize 1 gram of the polyester).

In preparing the polyester, the sum of the mole percent of theingredient (A) (1) above and ingredient (B) (1) above should constituteat least 20 mole percent of the polyester.

The resulting polyester can be dissolved in and subsequentlycopolymerized with any of the well-known ethylenically unsaturatedmonomers used as solvents and copolymerizable monomers for polyesters.Examples of such monomers include styrene, alpha-methyl styrene, vinyltoluene, divinyl benzene, chlorostyrene and the like, as well asmixtures of the above monomers.

The aforementioned U.S. Pat. No. 3,530,202 discloses an unsaturatedpolyester formed by the esterification of:

A. an unsaturated dicarboxylic acid anhydride consisting essentially of:

l. 7 to 15 mole percent of tetrahydrophthalic anhydride orendo-cis-bicyclo (2.2.1)-5-heptene-2,3-dicarboxylic acid anhydride andlower alkyl substituted products thereof; and

2. 35 to 43 mole percent of maleic anhydride; and

B. a dihydric alcohol reactant, namely 1,4-cyclohexanedimethanol. Themethod for preparing the polyester and the monomers with which they canbe polymerized are as set forth above in connection with the discussionof the polyester disclosed in U.S. Pat. No. 533,999.

The aforementioned U.S. Pat. No. 3,560,445 discloses an unsaturatedpolyester formed by the esterification of:

A. an unsaturated dicarboxylic anhydride consisting essentially of:

1. 5 to 44 mole percent of tetrahydrophthalic anhydride orendo-cis-bicyclo (2.2.1)-5-heptene-2,3dicarboxylic acid anhydride andlower alkyl substituted products thereof; and

2. 6 to 45 mole percent of maleic anhydride; and

B. a dihydric alcohol reactant consisting essentially of:

l. 5 to 40 mole percent of l,4-cyclohexane-dimethanol; and

2. 10 to 45 mole percent of a second dihydric alcohol;

wherein the sum of the mole percent of 1,4 cyclohexanedimethanol andingredient (A) (1) above is at least 20 mole percent of the polyester.

The method for preparing the polyester and the monomers with which theycan be polymerized are as set forth above in connection with thediscussion of the polyester disclosed in U.S. Pat. No. 3,533,999.

In a preferred embodiment of the invention described in U.S. Pat. No.3,560,445 it is taught that the polyester described therein, whensubsequently copolymerized with an ethylenically unsaturated monomersuch as styrene, yields a product which has superior chemical resistanceif the second dihydric alcohol used in the esterification is2,2-diemthyl-1,3- propanediol (neopentyl glycol). When neopentyl glycolis used as the second dihydric alcohol, the crosslinked polyesterwithstands not only water and caustic attack for longer periods of time,but resists acid attack as well.

The present invention relates to the modification of polyesters of thetype described hereinabove which modified polyesters can be cured intoproducts having even more improved thermal stability properties.

An object of this invention is to provide an unsaturated polyester whichupon being polymerized with a vinyl monomeric crosslinking agentproduces a thennoset plastic article which has improved thermalstability properties.

Another object of this invention is to provide a cured polyester resinwhich has, in addition to improved thermal stability properties, goodoverall physical and electrical proper- IIES.

SUMMARY OF THE INVENTION In accordance with this invention, it has beenfound that an unsaturated polyester condensate that is prepared byreacting a combination of specifically selected reactants can be used toprepare articles having outstanding thermal stability properties incombination with good overall properties, particularly electricalproperties. Generally speaking, the unsaturated polyesters includedwithin the scope of this invention are prepared by reacting:

A. an ethylenically unsaturated dicarboxylic acid;

B. an aliphatic saturated dicarboxylic acid for example, succinic,adipic, azelaic, etc., or a dimer or a trimer of an ethylenicallyunsaturated aliphatic monocarboxylic acid;

0. tetrahydrophthalic anhydride or endomethylene tetrahydrophthalicanhydride; and

D. a dihydric alcohol reactant comprising either cyclohexanedimethanolor a mixture of neopentyl glycol and a second dihydric alcohol.

With respect to the above ingredients, the term acid when used hereinincludes the anhydrides of those acids for which anhydrides exist. Thisis because the acid and its corresponding anhydride will react in thesame way in the esterification reaction.

It has been found that the unsaturated polyester prepared by reactingthe aforementioned ingredients can be reacted with a vinyl monomericcrosslinking agent and cured into articles that at ambient temperatureshave good overall properties, including particularly good electricalproperties. Upon subjecting the cured polyester resins to elevatedtemperatures for even extended periods of times the resins resistdegradation. Thus, they have excellent thermal stability properties. Thecured resins have a reduced tendency to volatize at elevatedtemperatures for example, at temperatures as high as 200 C even whenexposed thereto for prolonged periods of time for example, over 1 month.

Thus, the invention can be used to produce articles which can be used inapplications where very good electrical properties are needed and/or inapplications where the articles are exposed to elevated temperatures forprolonged periods of time. Under such conditions, the articles will tendto retain their mechanical and electrical properties. Examples ofarticles which can be prepared advantageously from the resins of thisinvention are filament wound tubes, cast insulators and electrical gradeshapes such as sheets, buckets and booms.

A very surprising facet of this invention is that the presence ofrelatively small amounts (about 1.0 mole percent of ingredient (B)above, that is the aliphatic saturated dibasic acid or theaforementioned dimer or trimer acids in the polyester results in a quiteremarkable improvement in its thermal stability properties. This will beappreciated more fully below in connection with the discussion of theexamples. It is noted also that as the amount of this ingredient isincreased, quite good improvements can be obtained in the flexibilityproperties of the cured resin. This provides for the production of curedpolyester articles which have a combination of properties hot heretoforeavailable.

As will be described more fully below, the unsaturated polyestersdescribed herein can be prepared under reaction conditions which aregenerally used in preparing heretofore known unsaturated polyesters andthey can be combined with other ingredients that are added generally topolymerizable polyester formulations which are curable and moldable intoarticles according to available techniques.

DETAILED DESCRIPTION OF THE INVENTION Turning now to a detaileddescription of the invention, the unsaturated polyester included withinthe scope of this invention comprises the esterification product of:

A. an acid reactant comprising:

1. about 15 to about 45 mole percent and preferably about 25 to about 40mole percent of an ethylenically unsaturated dicarboxylic acid;

2. about 1 to about 25 mole percent and preferably about 1 to about 12mole percent of an aliphatic saturated dicarboxylic acid or a dimer ortrimer of an ethylenically unsaturated aliphatic monocarboxylic acid;

. about 5 to about 20 mole percent and preferably about 10 to about 15mole percent of tetrahydrophthalic anhydride or endomethylenetetrahydrophthalic anhydride; and

B. a dihydric alcohol reactant comprising either cyclohexanedimethanolor a mixture of about 20 to about 40 mole percent and preferably about25 to 35 mole percent of neopentyl glycol and about 10 to about 30 molepercent and preferably about 15 to about 25 mole percent of a seconddihydric alcohol.

Each of the aforementioned reactants which are used to prepare theunsaturated polyesters of this invention and processes for preparing thereactants are well known.

As to the ethylenically unsaturated dicarboxylic acid component, it ispreferred to utilize either maleic anhydride or fumaric acid. Excellentresults have been achieved with these reactants; and they are readilyavailable. However, other acids from this class of compounds can beused. Examples of such acids are itaconic acid, citraconic acid,chloromaleic acid and mesaconic acid.

With respect to the aliphatic saturated dicarboxylic acids, they are awell recognized group of compounds. (For example, see Organic Chemistryby Paul Karrer, Nordeman Publishing Company, Inc., 1938). Includedwithin this group of compounds are acids, such as the following:succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid,azelaic acid, suberic acid, nonane-dicarboxylic acid,decane-dicarboxylic acid and undecane-dicarboxylic acid. Highermolecular weight acids can be used also, for example those containingeven 20 or more carbon atoms. In addition, mixtures of the acids can beused. Preferred acids are adipic, azelaic and sebacic.

It is recommended that the very low molecular weight aliphatic saturateddicarboxylic acids be not used in the polyesters of this invention whenthey are prepared at conventional reaction temperatures (for example, to220 C). Malonic acid (three carbon atoms) and oxalic acid (two carbonatoms) tend to decarboxylate at or below such reaction temperatures.Thus it is preferable to use an acid that is stable within the normaltemperature ranges used for polyesterification reactions. Generallyspeaking, this will include acids that have four or more carbon atoms.

Instead of utilizing an aliphatic saturated dicarboxylic acid to preparea polyester within the scope of this invention, there can be used adimer or trimer of an ethylenically unsaturated aliphatic monocarboxylicacid. Processes for the preparation of such dimers or trimers are wellknown; however, there is uncertainty regarding the exact structure ofsuch compounds. The dimer acid contains two carboxyl groups and thetrimer acid contains three carboxyl groups. Generally speaking, suchmaterials are prepared from ethylenically unsaturated aliphaticmonocarboxylic acids having between 14 and 22 carbon atoms. Examples ofsuch acids are myristoleic, oleic, linolenic, ricinoleic, etc. Thepreferred acid is the dimen'zed product of linoleic acid, an unsaturatedC fatty acid. The aforementioned dimers and trimers are sold by EmeryIndustries, Inc. as Empol dimer or trimer acids.

The reaction mixture should contain at least about 1 mole percent of thealiphatic saturated dicarboxylic acid or the aforementioned dimer ortrimer acids. When lesser amounts are used, there is a tendency for theimprovement in the thermal stability properties of the cured resinproduct to be relatively insignificant. n the other hand, if thereaction mixture contains more than about 25 mole percent of this acidreactant, there is a tendency for the cured resin product to be too softto permit sustained use at elevated temperatures. Cured resins withparticularly good combinations of properties have been prepared frompolyesters made from reaction mixtures that contain from about 1 toabout 12 mole percent of this acid reactant.

The tetrahydrophthalic anhydride component is a dicarboxylic anhydridecontaining a double bond. This anhydride, also referred to ascyclohexene-l,Z-dicarboxylic anhydride, can exist in various isomericforms, depending for example on the position of the double bond in thering. Excellent results have been obtained by utilizing4-cyclohexene-1,2-dicarboxylic anhydride (often referred to as delta-4tetrahydrophthalic anhydride) in preparing the polyesters of thisinvention. However, the l-,2-, or 3-cyclohexene-1,2-dicarboxylicanhydride isomer, as well as mixtures thereof, can be used also. Thefollowing U.S. patents disclose methods for preparing tetrahydrophthalicanhydrides: U.S. Pat. No. 2,764,597; U.S. Pat. No. 2,959,599; and U.S.Pat. No. 3,085,096.

Although it is preferred to use tetrahydrophthalic anhydride,endomethylene tetrahydrophthalic anhydride can be used instead. Examplesof the .latter are endo-cis-bicyclo (2.2.1 )-5-heptane-2,3-dicarboxylicanhydride and lower alkyl 1-4 carbon atoms) substituted productsthereof.

The reaction mixture should contain at least about 5 mole .percent oftetrahydrophthalic anhydride or endomethylene tetrahydrophthalicanhydride. When lesser amounts are used, there is a tendency for thermalstability properties of the cured resin product to be less thandesirable. On the other hand, if the reaction mixture contains more thanabout 20 mole percent of this acid reactant, there is a tendency for thecured resin product to be relatively soft or poor in strength. Curedresins with particularly good combinations of properties have beenprepared from polyesters made from reaction mixtures that contain fromabout to about mole percent of this acid reactant.

As to the dihydric alcohol reactant, it is noted that the unsaturatedpolyesters of this invention must be prepared from a reaction mixturethat contains either cyclohexanedimethanol or neopentyl glycol-thelatter always being used in combination with a second dihydric alcohol.When the former is used, it is not necessary to have another dihydricalcohol present in the reaction mixture. However, when neopentyl glycolis used, there must be in the reaction mixture a second dihydricalcohol. In the absence of another dihydric alcohol, the thermalstability properties of resultant cured product has a tendency to besomewhat less than desired. Examples of glycols that can be used incombination with neopentyl glycol are the following: ethylene glycol,propylene glycol and diethylene glycol.

With respect to the use of cyclohexane dimethanol, it is preferred toutilize the 1,4 isomer. Although it is not necessary to use a seconddihydric alcohol in combination with cyclohexanedimethanol, anotherdihydric alcohol can be used. Examples of such alcohols are mentionedabove in connection with the neopentyl glycol. Whencyclohexanedimethanol is used in combination with another glycol, theformer should comprise at least about 10 mole percent and preferably atleast about mole percent of the reaction mixture. It is preferred thatthe alcohol reactant comprise a mixture of both1,4-cyclohexanedimethanol and neopentyl glycol. Exceptionally goodresults are obtained with these diols.

A dihydric alcohol can be represented by the formula: R- (0H),, whereinR is an alkylene having from about two to about six carbon atoms,hydrogenated phenylene, hydrogenated biphenylene, or a hydrogenatedbis-phenol of the following formula:

II II wherein R R R and R are the same or different and are selectedfrom the group consisting of hydrogen and lower alkyl, and Y is a loweralkylene.

The unsaturated polyester of this invention can be prepared according toknown methods. Standard equipment and available techniques can beemployed. For example, the polyesterification reaction should be carriedout under an inert blanket of gas such as nitrogen and the reactionvessel should be equipped with a stirrer and means for removing thewater formed from the esterification reaction. In addition, a gelationinhibitor such as, for example, hydroquinone can be added to thereaction mixture. Also, the polyesterification reaction can be carriedout in the presence of an esterification catalyst.

Exemplary reaction temperatures and times are about C to about 210 C andabout 8 hours to about 10 hours respectively. Preferably, the reactionshould be allowed to proceed until the polyester has an acid numberwithin the range of about 20 to about 40.

In accordance with standard techniques, a two stage reaction can be usedwhen preparing polyesters from ingredients that have a relatively lowreactivity and which would have a tendency to cause the reaction mixtureto gel due to the polyesters reacting with themselves at the highertemperatures that would be needed to make the ingredients react at apractical rate.

The ratio of the amounts of acid reactant and alcohol reactant chargedto the reaction vessel can be a ratio used typically in apolyesterification reaction. Speaking generally, the total moles of acidpresent in the reaction mixture should be about equal to the total molesof alcohols used; however, it is preferred that there be charged to thereaction vessel an excess of about 5 mole percent of the alcoholreactant. The excess of the alcohol can compensate for losses due toboilingoff of the alcoholic ingredients.

Polymerizable compositions that can be molded and cured into articlescan be prepared by combining the unsaturated polyester described hereinwith available vinyl monomeric crosslinking agents which are capable ofpolymerizing with the unsaturated polyester. Examples of crosslinkingagents, which is noted contain the group, are styrene, vinyl toluene,alphamethyl styrene, cholorostyrene and tert-butylstyrene. Othercrosslinking agents can be used. Expedient amounts of the crosslinkingagent can be used. By way of example, a polymerizable composition cancontain about 50 to about 70 wt. percent of the polyester and about 30to about 50 wt. percent of the crosslinking agent.

A preferred crosslinking agent is vinyl toluene. As will be seen fromthe examples set forth below, excellent results have been obtained withthis material.

In addition, the polymerizable composition containing the unsaturatedpolyester and the crosslinking agent can contain other materials oftenincluded in this class of compositions. Examples of such materialsinclude fillers, initiators or catalysts, crosslinking and stabilizinginhibitors, accelerators or promoters, pigments, mold release additives,fibrous reinforcements, chemical thickening agents (such as for example,magnesium oxide) and thermoplastic polymers such as, for example,polystyrene, polymethylmethacrylate, styreneacrylonitrile copolymer aswell as others.

The polymerizable composition can be cured and molded into articlesaccording to available techniques including for .example, vacuum andpressure bag techniques and pultrusion;

or articles can be made in matched-metal molds utilizing premix or wetlay-up techniques. In addition, the polymerizable compositions can beformed into chemically thickened mats or prepregs which can be molded ina matched-metal mold.

EXAMPLES Examples set forth below are illustrative of compositionswithin the scope of this invention. The reaction equipment used toprepare the unsaturated polyesters described below included a reactionvessel suited for carrying out a polyesterification reaction and thusequipped with a stirrer, a reflux condenser and apparatus formaintaining the polyesterification reaction under an inert blanket ofnitrogen.

In each of the examples reported below, the tetrahydrophthalic anhydridereactant was the cis-delta-4 isomer; the molecular weight of theunsaturated polyester is the number average molecular weight; andviscosities of the polyester crosslinking agent solutions were measuredat room temperature with Brookfield Viscometers.

EXAMPLE 1 An unsaturated polyester was prepared from a reaction mixturecontaining the following:

Ingredients Moles maleic anhydride 2.0 azelaic acid 1.0tetrahydrophthalic anhydride 1.0 neopcntyl glycol 2.0 ethylene glycol2.2

EXAMPLE 2 An unsaturated polyester was prepared according to the methoddescribed in Example 1 from a reaction mixture containing:

Ingredients Moles maleic anhydride 2.0 azelaic acid 1.0tetrahydrophthalic anhydride 1.0 l,4-cyclohexanedimethanol 2.0 neopentylglycol 2.0

The condensate had an acid number of 27, a fumarate content of 73percent and a molecular weight of about 2,100. A solution containing 60wt. percent of the polyester and 40 wtfpercent of vinyl toluene had aviscosity of about 650 cps.

EXAMPLE 3 An unsaturated polyester was prepared as described in Example2, but from a reaction mixture that contained 0.75 mole of azelaic acidand 2.25 moles of maleic anhydride. The condensate had an acid number of27, a fumarate content of 66 percent and a molecular weight of about1,900.

EXAMPLE 4 An unsaturated polyester was prepared as described in Example2. The polyester condensate had an acid number of 24, a fumarate contentof 73 percent, and a molecular weight of about 1,900. A solutioncontaining 60 wt. percent of the polyester and 40 wt. percent of vinyltoluene had a viscosity of 650 cps.

EXAMPLE 5 An unsaturated polyester was prepared as described in Example2, but from a reaction mixture that contained 1.25 moles of azelaic acidand 1.75 moles of maleic anhydride. The reaction product had an acidnumber of 24, a fumarate content of 66 percent and a molecular weight ofabout 1,800.

Examples 6l0 below show the preparation of unsaturated polyesters withinthe scope of this invention made from reaction mixtures alike in allrespects except for the use of different aliphatic saturateddicarboxylic acids.

EXAMPLE 6 An unsaturated polyester was prepared as described in Example2, but from a reaction mixture that contained 1 mole of succinic acidinstead of 1 mole of azelaic acid. The condensate had an acid number of31.

EXAMPLE 7 An unsaturated polyester was prepared as described in Example2, but from a reaction mixture that contained 1 mole of adipic acidinstead of 1 mole of azelaic acid. The polyester had an acid number of22, a fumarate content of 81 percent, and a molecular weight of about2,000. A solution containing 60 wt. percent of the condensate and 40 wt.percent of vinyl toluene had a viscosity of 800 cps. A solutioncontaining 60 wt. percent of the condensate and 40 wt percent oftert-butylstyrene had a viscosity of 4,500 cps.

EXAMPLE 8 An unsaturated polyester was prepared as described in Example2 but from a reaction mixture that contained 1 mole of sebacic acidinstead of 1 mole of azelaic acid. The polyester had an acid number of23, a fumarate content of 76 percent and a molecular weight of about2,100. A solution containing 60 wt. percent of the polyester and 40 wt.percent of vinyl toluene had a viscosity of about 900 cps.

EXAMPLE 9 An unsaturated polyester was prepared as described in Example2, but from a reaction mixture that contained 0.5 mole of azelaic acidand 0.5 mole of adipic acid instead of 1 mole of azelaic acid. Thepolyester had an acid number of 23, a fumarate content of 73 percent anda molecular weight of about 2,200. A solution containing 60 wt. percentof the polyester and 40 wt. percent of vinyl toluene had a viscosity of750 cps. A solution containing 60 wt. percent of the polyester and 40wt. percent of tert-butylstyrene had a viscosity of 3,100 cps.

EXAMPLE 10 An unsaturated polyester was prepared as described in Example2, but from a reaction mixture that contained 1 mole of an aliphaticdimer acid a C ethylenically unsaturated aliphatic dibasic acid preparedby polymerizing unsaturated C fatty acids and sold as Empol Dimer 1014)instead of 1 mole of azelaic acid. The polyester had an acid number of26,

a fumarate content of 56 percent and a molecular weight of about 2,200.A solution containing 60 wt. percent of the polyester and 40 wt. percentof vinyl toluene had a viscosity at room temperature of about 450 cps.

Examples 1 l and 12 below show the preparation of unsaturated polyesterswithin the scope of this invention from reaction mixtures which containglycols, other than neopentyl glycol, in combination with1,4-cyclohexanedimethanol.

EXAMPLE 1 1 An unsaturated polyester was prepared as described inExample 2, but from a reaction mixture that contained 2 moles ofethylene glycol instead of 2 moles of neopentyl glycol. The product hadan acid number of 24, a fumarate content of 59 percent and a molecularwt. of about 1,700. A solution containing 60 wt. percent of thepolyester and 40 wt. percent of vinyl toluene had a viscosity of 500cps.

EXAMPLE 12 An unsaturated polyester was prepared from a reaction mixturecontaining the following:

2,2,4-trimethylpentanediol 1.91

The trimethylpentanediol, azelaic acid, tetrahydrophthalic anhydride andmaleic anhydride ingredients were charged to the reaction vessel. Thereaction mixture was heated for 7 hr. at 175 C and then cooled to about100 C. The cyclohexanedimethanol ingredient was added to the reactionmixture and heating was continued for 3 hr. at 200 C. The polyester hadan acid number of 40, a fumarate content of 92 percent, and a molecularweight of about 1,200. A solution containing 60 wt. percent of thepolyester and 40 wt. percent of vinyl toluene had a viscosity of 350cps. A solution containing 60 wt. percent of the polyester and 40 wt.percent of tertbutylstyrene had a viscosity of 1,900 cps.

Examples 13-17 below show the preparation of polyesters within the scopeof this invention from reaction mixtures alike in all respects exceptfor the use of different amounts of maleic anhydride and adipic acid.

EXAMPLE 13 An unsaturated polyester was prepared according to the methoddescribed in Example 1 from a reaction mixture containing:

EXAMPLE 14 An unsaturated polyester was prepared as described in Example13, but from a reaction mixture that contained 0.5 mole of adipic acidand 2.5 moles of maleic anhydride. The resulting polyester had an acidnumber of 29.

EXAMPLE 15 An unsaturated polyester was prepared as described in Example13, but from a reaction mixture that contained 1 mole of adipic acid and2 moles of maleic anhydride. The polyester had an acid number of 22.

EXAMPLE 16 An unsaturated polyester was prepared as described in Example13, but from a reaction mixture that contained 1.5 moles of adipic acidand 1.5 moles of maleic anhydride.

EXAMPLE 17 An unsaturated polyester was prepared as described in Example13, but from a reaction mixture that contained 2 moles of adipic acidand 1 mole of maleic anhydride. The polyester had an acid number of 30.

The next example is illustrative of a polyester within the scope of thisinvention that can be prepared from a long chain tricarboxylic acid.

EXAMPLE 18 An unsaturated polyester is prepared from a reaction mixturecontaining 2.98 moles of maleic anhydride, 0.02 mole of a trimer acid(Empol 1040), 1 mole of tetrahydrophthalic anhydride and 2 moles each ofneopentyl glycol and 1,4- cyclohexanedimethanol.

The excellent thermal stability and generally good overall properties ofcured polyester resins within the scope of this invention areexemplified in test results reported in Tables l-5 below. The testresults were obtained by subjecting castings made from polyesters of theabove examples to the various tests identified in the table.

Test castings were prepared from the polyesters of Example 1, Examples39 and Examples 1 l-l 7 as follows. A solution of 60 wt. percent of theunsaturated polyester of the example and 40 wt. percent of vinyl toluenewas prepared. To this solution there was added 0.75 wt. percent based onthe weight of the solution of powdered benzoyl peroxide crosslinkingcatalyst. The solution was cured between two glass panes into a V8 inchthick casting by heating for 2 hours at 75 C and then for 2 hours at C.The castings are identified in the tables below by the example number ofthe composition from which it was made followed by the letter C.

Test castings were prepared also from the polyesters of Examples 2 and10 according to the following method. A solution of 60 wt. percent ofthe polyester of the example and 40 wt. percent of vinyl toluenecrosslinking agent was prepared. To this solution there was added 0.75wt. percent based on the weight of the solution of 2,5dimethylhexane-2,5-diper (2- ethyl) hexoate (USP-245). The solution wascured between 2 glass panes into a Vs inch coasting by heating for 2hours at 60 C, 1 hour at 75 C and 2 hours at 150 C. The castings areidentified in the tables as Ex. 2C and Ex. 10C.

As will be observed, the tables show the extent to which the castingsresist degradation as a result of volatilization due to heating at thetemperatures indicated in the tables and for the periods of time setforth. These tests were carried out by placing the castings in acirculating air oven. The approximate dimensions of the castings were 4:X k X 1.5".

It is noted that the test results are expressed in percent loss ofweight of the casting-the lower percent loss of weight, the better thethermal stability properties. Other properties, measured by conventionaltests, are reported in the tables also.

In Table 1 below, there are shown the properties of test castings madefrom compositions alike in all respects except for the polyesters whichdiffer because they were made from reaction mixtures that containedvarying amounts of azelaic acid and maleic anhydride. In Table 1 underthe example number, the number of moles of the azelaic acid is set forthand it is followed by the number of moles of maleic anhydride.

TABLEfiT SAMPLES percent weight loss of the casting at 260 C was 3 1after only I w PROPERTIES Ex- 3C Ex 4C Ex. C eek (compared to 6.6percent the highest value reported in 075/225) 1/2 1.25/ table) 175) InTable 3 below there are shown the test results of castings ASTM D438 5made from polyesters which contained different dihydric al- Ten.Strength, psi 8,100 7,800 5.000 coho! reactants. Modulus X IO", psi 406394 28] TABLE 3 Elongation 3.1 3.3 6.9 Weight lost at TEST SAMPLE 220Cafterz6 wk. 5.8 5.7 7.1 1C E 11C Ex. 12C weight 1 at neopentyl ethylene2,2,4-tri- 260C after: 1 wk. 6.4 6.2 7.3 Properties glycol & glycol &methylpentane- 6 wk. I2 l I I4 ethylene glycol I,4-cyclo. diol 8tl,4-cyclo.

The extent to which the presence of even very small ASTM 0-638 I amountsof the azelaic acid reactant influences the thermal zi s 6 400 6 300stability properties of the cured resin can be appreciated whenElongation 60 M 18 it is considered that a casting made from anunsaturated Weight 1 at polyester alike in all respects to that ofExample 3, except for 220C aft"! 1 the absence of the azelaic acidcomponent and the use of 3 2 wk. 7.0 4.8 7.0 moles of maleic anhydride,had a weight loss of 31 percent 3 wk after a 1 week exposure to atemperature of 260 C (compared 4 wk. 8.4 6.1 8.2 to the 6.4 percentofthe casting ofExample 3C). 5 wk. 6.4 8.7 In Table 2 below there is setforth the properties of test g g at castings made from polymerizablecompositions containing 260C f 1 the polyesters of Example 2 and 6-I0which are alike in all 9.4 7.2 respects except for the use of differentaliphatic saturated 11 dibasic acids. It is noted that the casting ofExample 2C was 4 l3 cured under different conditions than those ofExamples 5 14 6C-l0 C as mentioned hereinabove. 6 l5 TABLE 2 Testsamples Ex. Ex. Ex. 10C Ex. 20 Ex. 60 Ex. 70 (sebacic (azelaie (dimerProperties (azelaic) (suceinic) (adipic) acid) and adipic) acid) ASTMD-638:

Tensile strength, p.s.i 7,800 J, 300 8,600 7,400 8,000 2, 400 Percentelongation 5. 2 3.1 6. 7 3.1 3. 8 9. 8 Percent weight lost at 220 C.

after- 1 week 3.5 3. 3 3. 7 4. 6 2 Wee 4. 3 4. 0 4. 7 5.1 3 Wee 4. 8 4.2 5. 1 5. G 4 weeks 5.2 4.2 5.7 5.6 5 weeks. 5.4 4. 3 5.9 6.0 6 weeks.5. 7 4. 5 5. 9 6. 2 Percent weight lost at 260 C.

after-- 1 week 5. 9 5. 7 6, 5 6. 3 2 weeks. G. 9 0. 5 8. 4 8. 9 3weeks... 7. 8 7. 2 9. 8 3 4 weeks. 8.6 7. 5 12 20 5 weeks... 9. 0 8. 214 25 6 weeks 11 8. 6 15 2 Estimated from measurement taken after 7%weeks.

In connection with the weight loss properties reported in Table 2 above,it is noted that a casting made from a composition alike in all respectsto those from which the castings identified in the table were made,except that the unsaturated polyester was made from a reaction mixturethat contained no aliphatic saturated dicarboxylic acid and 3 moles ofmaleic anhydride, had thermal stability properties at 220 C which weresomewhat similar to castings of the table; but surprisingly, the

In Table 4 below, there are shown the properties of various castingsmade from polymerizable compositions alike in all respects except forthe use of polyesters made from reaction mixtures that containeddifferent concentrations of the adipic acid and maleic anhydridecomponents. In the table under the example number, the number of molesof adipic acid is set forth and it is followed by the number of moles ofmaleic anhydride.

IABLE 4 Test samples Ex. 130 EX. 14C Ex. 15C Ex. 10C Ex. 17C Properties(0.1/2.9) (0.5/2.5) (1/2) (1.5/1.5) (2/1) ASTM D-638:

Tensile strength, p.s.i 2,900 3, 700 8, G00 4, 900 1,800 Percentelongation 0.7 0. 8 6. 7 3.3 13 Deflection temp., F 251 108 158 Percentweight lost at 220 C.

atte

10 4.3 (L5 7.4 0.2 1'.) 5. 2 8.4 H. (I I0 .20 5. .1 U. is 10 II (i. 3 12I1 I] 7. 0 14 I2 12 6 weeks 7.5 15 l2 l3 Defiected under load at 77 F.

Attention is directed to Example 13C in Table 4 above. it is noted thatthe amount of adipic acid that was used in preparing the unsaturatedpolyester that was used in making the casting of this example was very,very small, that is, 0.1 mole l .25 mole percent). However, the thermalstability properties of the casting at 260 C were very much better thana casting prepared from an unsaturated polyester that contained noadipic acid, that is, one prepared from a polyester that was made from areaction mixture alike in all respects to that of Example 13, butcontaining no adipic acid and 3 moles of maleic anhydride. The percentwt. loss of such a casting was 31 after l-weeks exposure to atemperature of 260 C compared to the 10 percent wt. loss of the castingof Example 1 3C. This comparison highlights the significant thermalstability improvements that are attained when even very, very smallamounts of the aliphatic saturated dicarboxylic acid is used.

To'illustrate the generally good electrical and physical properties ofcured polyester resins within the scope of this invention, there is setforth below in Table electrical properties of castings made from thepolyester of Example 4 above. In addition, there is set forth also theelectrical properties of a cured polyester prepared as described inExample 2 above, but from a reaction mixture that contained 1 mole ofadipic acid instead of 1 mole of azelaic. The polyester (Example 19) hadan acid number of 25, a fumarate content of 75 percent and a molecularweight of about 2,000. A casting was prepared from this polyester in thesame manner as the casting of Example 4C. The casting is identified inTable 5 as Example 19C.

TABLE 5 Casting, Casting, Example Example 40 (azaieic 19C (adipic Testacid) acid) Electrical properties:

ASTM

Insulation resistance (ohms) 8. 3%10H 5. 3X10H Volume resistivity(ohms-cm) 6.0)( 7. 7X10" Surface resistivity (ohms) 1. 5X10H 1. 9X10AS'IM l)150:

Dielectric constant, (60 ii rt1.) 3. 31 3. 46 Dissipation lnetor, ((30liertz)... 0.004 0.004 ASTM l)14il:

Dielectric strength, short time (1)- (volts/mil) 418 455 Dielectricstrength, short time (11) ASTM D-495:

Arc resistance ($00.) 124 129 Track resistance (min.) 900+ 900+ Physicalproperties:

ASTM 13-790; Flexural strength, room temp. (p.s.1.) 12, 300 13, 200Flexural modulus, room temp. (p.s.i.) 332, 000 359, 000

AS'IM D-648-56: deflection temp. F.). 152 159 ASTM D-2583-67: Barcolhardness 35 35 Additional test castings were made from the compositionsof Examples 3-5 and 7-9 utilizing as the crosslinking agenttert-butylstyrene instead of vinyl toluene. The castings were preparedby utilizing the method used to prepare the castings of Examples 1C,3C-9C and l lC-l7C. Testing the properties of these castings showed thatin general the cured compositions shrunk less when tert-butylstyrene wasused as the crosslinking agent, but that the overall thermal stabilityof the cured resins was not quite so good as the castings made from thecompositions that were crosslinked with vinyl toluene.

.In addition, a filled glass mat was prepared from the unsaturatedpolyester of Example 19 as follows. Using a mechanical stirrer, 3,080 g.of a resinous composition containing 60 wt. percent of the polyester and40 wt. percent of vinyl toluene and 2,640 g. of ASP 600 (aluminumsilicate sold by Engelhard industries) were mixed thoroughly. A secondmixture comprised of 880 g. of the aforementioned resinous compositionand 29.7 g. of 2,5-dimethylhexane2,5-diper (Z-ethyl) hexoate was thenblended with the first mix and the resultant paste was applied by handin a uniform manner to four plies of l )2 oz. chopped strand glass matand four plies of glass surface mat (two on each surface). Thissandwich-type composite was 75 molded in a VB X X14 inch cavity for 5min. at 240 F. and

350 psi. After being subjected to a temperature of 230 C for 6 weeks,the cured product had a weight loss of only 4.3 percent; its dilelectricstrength was 457 ST( 1 volts/mil.

The unsaturated polyester of Example 19 was used also to preparefilament wound tubes in the following manner. A bath containing 60 wt.percent of the unsaturated polyester and 40 wt. percent of vinyl toluenewas prepared. To the bath, 1 percent by wt. of benzoyl peroxide wasadded. Continuous glass strand roving was passed through the bath andwound at ambient temperature onto a steel mandrel having a 2 inchdiameter using techniques and equipment which are well known in the art.The mandrel onto which the laminate had been wound was then rotatedslowly for 2 hr. in an oven maintained at about 100 C. to gel the resin.Post-curing for 4 hr. at 150 C. followed. A filament-wound tube havingnominal wall thickness of one-eighth inch was obtained; its glasscontent was about 20 percent. Percent weight losses of samples of thetubes after being exposed for 6 weeks to temperatures of 190 C, 210 Cand 230 C were 1.3,7.7 and 9.7 respectively.

We claim:

1. An unsaturated polyester consisting essentially of the esterificationproduct of:

a. about 15 to about 45 mole percent of an ethylenically unsaturateddicarboxylic acid;

b. about 1 to about mole percent of an aliphatic saturated dicarboxylicacid or a dimer or trimer of an ethylenically unsaturated aliphaticmonocarboxylic acid having about 14 to about 22 carbon atoms;

. about 5 to about 20 mole percent of tetrahydrophthalic anhydride orendomethylene tetrahydrophthalic anhydride; and

. dihydric alcohol reactant selected from the group consisting ofcyclohexanedimethanol and a mixture of about 20 to about 40 mole percentof neopentyl glycol and about 10 to about mole percent of a seconddihydric alcohol wherein the total mole percent of the acid reactants of(a), (b), and (c) and the dihydric alcohol reactant are about equal.

2. A polymerizable composition comprising:

a. the unsaturated polyester of claim 1; and b. a vinyl monomer capableof crosslinking with said polyester to form a thermoset polymer.

3. A composition according to claim 2, wherein said vinyl monomer isvinyl toluene.

4. An unsaturated polyester consisting essentially of the esterificationproduct of:

A an acid reactant consisting essentially of:

1. about 15 to about 45 mole percent of an unsaturate selected from thegroup consisting of maleic anhydride and fumaric acid;

2. about 1 to about 25 mole percent of an aliphatic saturateddicarboxylic acid or a dimer or trimer of an ethylenically unsaturatedaliphatic monocarboxylic acid having about 14 to about 22 carbon atoms;

3. about 5 to about 20 mole percent of tetrahydrophthalic anhydride orendomethylene tetrahydrophthalic anhydride; and

B. a dihydric alcohol selected from the group consisting of1,4-cyclohexanedimethanol and a mixture of about 20 to about molepercent of neopentyl glycol and about 10 to about 30 mole percent of asecond dihydric alcohol;

wherein the total mole percent of each of the acid and dihydric alcoholreactants are about equal.

5. An unsaturated polyester in accordance with claim 4 wherein saidsaturated dicarboxylic acid is selected from the group consisting ofsuccinic, adipic, azelaic and sebacic acids and mixtures thereof.

6. An unsaturated polyester in accordance with claim 4 wherein reactant(A) (2) is said dimer acid and wherein said dimer acid is prepared froma C fatty acid.

7. An unsaturated polyester resin in accordance with claim 4 whereinsaid dihydric alcohol reactant is a mixture of neopenty] glycol andl,4-cyclohexanedimethanol.

8. A polymerizable composition comprising:

A. the unsaturated polyester of claim 4; and B. a vinyl monomer capableof crosslinking with said polyester to form a thermoset polymer.

9. A composition according claim 8 wherein said vinyl monomer is vinyltoluene.

10. An unsaturated polyester consisting essentially of theesterification product of:

A. an acid reactant consisting essentially of:

1. about 25 to about 40 mole percent of an unsaturate selected from thegroup consisting of maleic anhydride and fumaric acid;

2. about 1 to about 12 mole percent of an aliphatic saturateddicarboxylic acid or a dimer or trimer of an ethylenically unsaturatedaliphatic monocarboxylic acid having about 14 to about 22 carbon atoms;

about to about 15 mole percent of tetrahydrophthalic anhydride orendomethylene tetrahydrophthalic anhydride; and B. a dihydric alcoholelected from the group consisting of 1,4-cyclohexanedimethanol and amixture of about 25 to about 35 mole percent of neopentyl glycol andabout 15 to about 25 mole percent of a second dihydric alcohol; whereinthe total mole percent of each of the acid and dihydric alcoholreactants are about equal.

11. An unsaturated polyester in accordance with claim 10 wherein saidsaturated dicarboxylic acid is selected from the group consisting ofsuccinic, adipic, azelaic and sebacic acids and mixtures thereof.

12. An unsaturated polyester in accordance with claim 10 whereinreactant (A) (2) is said dimer acid and wherein said dimer acid isprepared from a C fatty acid.

13. An unsaturated polyester in accordance with claim 10 wherein saiddihydric alcohol reactant is a mixture of neopentyl glycol and1,4-cyclohexanedimethanol.

14. A polymerizable composition comprising:

a. the unsaturated polyester of claim 10; and

b. a vinyl monomer capable of crosslinking with said polyester to form athermoset polymer.

15. A composition according to claim 14, wherein said vinyl monomer isvinyl toluene.

16. A polymerizable composition comprising:

A. the unsaturated polyester of claim 11; and

B. a vinyl monomer capable of crosslinking with said polyester to form athermoset polymer.

17. A composition according claim 16 wherein said vinyl monomer is vinyltoluene.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. a ,s'lu,727 Dated July 1972 v fl Frank Fekete and John S. McNally It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 18, "polymer" should read -polyester--.

Column 2, line 51, "533,999" should read --3,533,999-.

Column 10, line 55', "coasting" should read -casting-.

Column 11, Table l, "5.8" to the left of "5.7" should be read in thecolumn immediately to the right of "5.7".

Column 11, Table 2, last column, "5.6" second occurrence, should read--5.8.

Column 13, Table 5, first entry of middle column, "8.3 1/4" 7 shouldread -8. 3X-.

IN THE CLAIMS Claim 10, line 1 "elected" should read -selected.

Claim 17, line 1, read -to-- after "according".

Signed and sealed this 9th day of January 1973.

(SI-1A1.)

Attest:

EDWARD M.FLETCHER,JR. I ROBERT GO'I'TSCI'IALK Attcsting OfficerCommissioner of Patents FORM PO-IOSO (10-69) USCOMM-DC 60376-P69 h uis.GOVERNMENT PRINTING OFFICE: 1959 c ass-334

2. about 1 to about 12 mole percent of an aliphatic saturateddicarboxylic acid or a dimer or trimer of an ethylenically unsaturatedaliphatic monocarboxylic acid having about 14 to about 22 carbon atoms;2. about 1 to about 25 mole percent of an aliphatic saturateddicarboxylic acid or a dimer or trimer of an ethylenically unsaturatedaliphatic monocarboxylic acid having about 14 to about 22 carbon atoms;2. A polymerizable composition comprising: a. the unsaturated polyesterof claim 1; and b. a vinyl monomer capable of crosslinking with saidpolyester to form a thermoset polymer.
 3. A composition according toclaim 2, wherein said vinyl monomer is vinyl toluene.
 3. about 5 toabout 20 mole percent of tetrahydrophthalic anhydride or endomethylenetetrahydrophthalic anhydride; and B. a dihydric alcohol selected fromthe group consisting of 1,4-cyclohexanedimethanol and a mixture of about20 to about 40 mole percent of neopentyl glycol and about 10 to about 30mole percent of a second dihydric alcohol; wherein the total molepercent of each of the acid and dihydric alcohol reactants are aboutequal.
 3. about 10 to about 15 mole percent of tetrahydrophthalicanhydride or endomethylene tetrahydrophthalic anhydride; and B. adihydric alcohol elected from the group consisting of1,4-cyclohexanedimethanol and a mixture of about 25 to about 35 molepercent of neopentyl glycol and about 15 to about 25 mole percent of asecond dihydric alcohol; wherein the total mole percent of each of theacid and dihydric alcohol reactants are about equal.
 4. An unsaturatedpolyester consisting essentially of the esterification product of: A anacid reactant consisting essentially of:
 5. An unsaturated polyester inaccordance with claim 4 wherein said saturated dicarboxylic acid isselected from the group consisting of succinic, adipic, azelaic andsebacic acids and mixtures thereof.
 6. An unsaturated polyester inaccordance with claim 4 wherein reactant (A) (2) is said dimer acid andwherein said dimer acid is prepared from a C18 fatty acid.
 7. Anunsaturated polyester resin in accordance with claim 4 wherein saiddihydric alcohol reactant is a mixture of neopentyl glycol and1,4-cyclohexanedimethanol.
 8. A polymerizable composition comprising: A.the unsaturated polyester of claim 4; and B. a vinyl monomer capable ofcrosslinking with said polyester to form a thermoset polymer.
 9. Acomposition according claim 8 wherein said vinyl monomer is vinyltoluene.
 10. An unsaturated polyester consisting essentially of theesterification product of: A. an acid reactant consisting essentiallyof:
 11. An unsaturated polyester in accordance with claim 10 whereinsaid saturated dicarboxylic acid is selected from the group consistingof succinic, adipic, azelaic and sebacic acids and mixtures thereof. 12.An unsaturated polyester in accordance with claim 10 wherein reactant(A) (2) is said dimer acid and wherein said dimer acid is prepared froma C18 fatty acid.
 13. An unsaturated polyester in accordance with claim10 wherein said dihydric alcohol reactant is a mixture of neopentylglycol and 1,4-cyclohexanedimethanol.
 14. A polymerizable compositioncomprising: a. the unsaturated polyester of claim 10; and b. a vinylmonomer capable of crosslinking with said polyester to form a thermosetpolymer.
 15. A composition according to claim 14, wherein said vinylmonomer is vinyl toluene.
 16. A polymerizable composition comprising: A.the unsaturated polyester of claim 11; and B. a vinyl monomer capable ofcrosslinking with said polyester to form a thermoset polymer.
 17. Acomposition according claim 16 wherein said vinyl monomer is vinyltoluene.